Active surveillance for favorable-risk prostate cancer: who, how and why?

Active surveillance for favorable-risk prostate cancer has become increasingly common in populations in which screening for prostate cancer is widespread, owing to evidence that in many patients screening results in the detection of disease that is not clinically significant (i.e. untreated, it would not pose a threat to health). The approach is supported by data demonstrating that patients who have clinically insignificant disease can be identified with reasonable accuracy, and that patients who are initially classified as low risk but reclassified over time as higher risk and are treated radically are still cured in most cases. It is important to identify patients who have a low probability of disease progression during their lifetime according to clinical and pathologic features of the disease, patient age and comorbidity. Close monitoring of patients over time and availability of reasonable criteria for intervention, which will both identify more-aggressive disease in a timely fashion and not result in excessive treatment, are crucial. It is also important to communicate appropriately with the patient, to reduce the psychological burden of living with untreated cancer. The results of active surveillance, the criteria for patient selection and the appropriate thresholds for intervention are reviewed in this article.